Window unit

ABSTRACT

A window unit comprises a frame which surrounds a frame opening elongated in horizontal direction. A pair of window panels are received within the confines of the frame and together close the opening. Means mounts at least one of the window panels for horizontal sliding movement in the general plane of the opening as well as for tilting movement transversely to this general plane.

Unite States Patent Schmidlin [54] WINDOW UNIT [72] Inventor: HansSchmidlin, Bruelweg 47, Aesch,

Switzerland [22] Filed: Aug. 11, 1970 9/1955 Schoen ..49/223 X Feb.15,1972

3,120,033 2/1964 Andres ..49/420 FOREIGN PATENTS OR APPLICATIONS 88,6820/1957 Norway ..49/155 Primary Examiner-Kenneth Downey Att0rney-MichaelS. Striker [5 7] ABSTRACT A window unit comprises a frame whichsurrounds a frame opening elongated in horizontal direction. A pair ofwindow panels are received within the confines of the frame and togetherclose the opening. Means mounts at least one of the window panels forhorizontal sliding movement in the general plane of the opening as wellas for tilting movement transversely to this general plane.

12 Claims, 1 1 Drawing Figures PAIENTEUFEB 15 m2 SHEET 2 OF 2 INVI'ZNTORHANS SCHMIDLIN ATTORNEY WINDOW UNIT This is a continuation of my earlierapplication Ser. No. 814,428, filed on Apr. 8, 1969 and now abandoned.

BACKGROUND OF THE INVENTION The present invention relates to a windowunit in general, and more particularly to a window unit utilizing windowpanels at least one of which is horizontally slidable as well astiltable transversely of the direction of sliding movement.

Window units of the type in question are already known. They enjoyincreasing popularity in private rooms, offices, schools and in similarapplications because on the one hand they make it possible to expose alarge area of the frame opening completely, if this is desired, whereason the other handthat is if the appropriate window panel is tilted outof the general plane of the opening of the window frameonly a relativelysmall opening will be provided in the window for ventilation purposes.

One construction of this type which is known to me suffers from avariety of disadvantages, including relatively complicated construction,relatively complicated operation, the fact that when the tiltable panelis tilted only a small and inadequate opening will be provided which isnot sufficient to provide proper ventilation, and other problems. Amongthese should be mentioned that this known construction providesinadequate sealing in the closed position of the window unit.

SUMMARY OF THE INVENTION The present invention has as its general objectto overcome these disadvantages.

More particularly, it is an object of the present invention to provide acombination window unit having at least one panel which is slidablehorizontally and which can also be tilted out of the general plane ofthe window opening with a resultant gap which is large enough to provideadequate ventilation.

An additional object of the invention is to provide such a window unitwhich is to reliably be tight under all circumstances when it is closed.

A concomitant object of the invention is to provide such a window unitwhich is uncomplicated in its construction and simple to use.

In accordance with one feature of my invention, I provide a window unitwhich comprises a frame surrounding a frame opening elongated inhorizontal direction, and a pair of window panels received within theconfines of the frame and together closing the opening thereof. Finally,I provide means mounting at least one of the window panels forhorizontal sliding movement in the general plane of the opening as wellas for tilting movement transversely to the general plane.

By contrast, the known window unit of the type under discussion requireswhenever the window is to be opened that the movable window panel firstbe tilted out of the general plane of the window opening and that itthen be drawn inwardly into the interior of the room provided with thewindow unit until it is again located in a plane parallel to its closureplane. Only then can it be horizontally moved but not in the generalplane of the frame opening.

In accordance with my invention, I have found it advantageous if atleast the uppennost frame portion bounding the opening is provided witha ridge extending horizontally as well as projecting into the opening indownward direction, with at least the uppermost edge portion of themovable panel being provided with a channel in which the ridge can besealingly sealed. If my window unit is constructed in this manner, thenit is necessary, in order to permit tilting of the movable panel, thatthe unit be provided with lifting means or shifting means which normallylifts the movable panel up wardly so that the ridge is received in thechannel, and which lowers the panel when it is desired to tilt the same,whereby the ridge is withdrawn from the channel and does not impede thetilting movement of the panel.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of awindow unit or assembly according to the present invention, as would beseen from the interior of a room in which it is installed, and with onemovable panel in closed condition;

FIG. 2 is a view similar to FIG. I but with the movable panel shown ininwardly tilted condition;

FIG. 3 is a view similar to FIG. 2 but with the movable panel shownhorizontally displaced;

FIG. 4 is a fragmentary section on an enlarged scale of the sealingconnection between the upper edge of the movable panel and the frame.

FIG. 5 illustrates the view of FIG. 4 but with the movable panel inlowered condition;

FIG. 6 is a fragmentary detailed view illustrating the upper connectionof the movable panel with the frame;

FIG. 7 is a diagrammatic detail view on an enlarged scale and partly invertical section showing the means for lifting the movable panel;

FIG. 8 is a fragmentary top plan detail view of portions of FIG. 7;

FIG. 8a is a section on line VIIIA-VIIIA of FIG. 7;

FIG. 9 is a view similar to FIG. 7 but showing the panel in loweredcondition; and

FIG. 10 is a diagrammatic detail view partly in vertical section and onan enlarged scale, of the roller cages shown in FIGS. 7 and 9.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing now the embodimentillustrated in FIGS. 1-6, it will be seen that the frame of my novelunit or assembly is generally identified with reference numeral 4. It iselongated in horizontal direction and bounds a window opening in whichthere are received two window panels I, la which together close thewindow opening. In the illustrated embodiment both of the panels I, laare slidable in horizontal direction, that is in the direction ofelongation of the opening of the frame 4, as indicated by the arrows,but it is evident that only one of the panels need be so slidable if itis desired.

FIG. 1 illustrates the window unit in closed condition. FIG. 2illustrates that the window panel is not only slidable in the directionof elongation of the opening of the frame 4, but also tiltably inwardlyinto the room in which the window is assumed to be installed. As evidentfrom FIGS. 1 and 3, the panel 1 can be slidingly displaced in thedirection of the arrow associated therewith not only when it is in theposition shown in FIG. 1, that is when it is located in the generalplane of the opening of the frame 4, but also when it is tilted inwardlyout of this general plane, as shown in FIG. 3.

In accordance with well-known practice, the panels I, la will usually beconstituted of glass which is secured in its own frame of wood, metal,plastic or the like. Details concerning this need not be discussedbecause they are well known. It is pointed out, however, that inaccordance with the present invention and as illustrated in FIG. 4, theupper portion of the frame 4 is provided with a downwardly extending ribor ridge 3 extending in the longitudinal direction of the opening in theframe 4. Conversely, the upper portion of the frame of at least thewindow panel 1 is provided with a channel 2 into which the ridge 3extends when the panel is in the position illustrated in FIG. I. Sealingmeans may be provided, for instance, on the side walls bounding thechannel 2, as in FIGS. 4 and 5 illustrated in form of brushlike sealingstrips 5. Of course, other sealing means can also be used. The purposeis to assure that the sealing means 5 will engage the rib 3 when thesame is received in the channel 2 so as to provide a seal against dust,moisture and the like.

It will be understood, of course, that the same type of sealingarrangement will also be provided on the panel In, although if thelatter is not tiltable in the manner of the panel I, the rib 3 willremain in constant engagement with the sealing means 5.

If the embodiment of FIG. 4 is chosen, that is the embodiment where therib 3 extends into the channel 2, tilting of the panel 1 in manner shownin FIGS. 2 and 3 would be impossible unless adequate provision is made.Accordingly, I provide means for raising and lowering the panel 1 inmanner indicated in FIG. 1 by double-headed arrow. This means will bediscussed subsequently with respect to FIGS. 7-10. At the present timeit will suffice to point out that in FIG. 4 the panel 1 is shown in itsuppermost position in which the rib 3 is received in the channel 2 insealing engagement with the sealing means 5, whereas in FIG. 5 I showthe panel 1 in its lowermost position wherein the rib 3 is withdrawnfrom the channel 2. Actually, it would be more accurate to state thatchannel 2 has been downwardly withdrawn away from the rib 3. Be that asit may, because the rib 3 is now no longer received within the confinesof the channel 2, the panel 1 can be tilted in the manner illustrated inFIGS. 2 and 3.

Of course, when the panel I is to be tilted, it is necessary to preventit from falling entirely out of the frame 4. As shown in FIG. 6, Iprovide means for preventing this, such means having the form of glidersor guide blocks 8 (only one shown) which are engaged in the uppermostportion of the frame 4 and are slidable in the longitudinal direction ofthe frame opening. There are two such gliders 8 provided located atopposite lateral edges of the panel 1, but only one thereof togetherwith its associated components will be described because they are bothidentical. The glider 8 pivotally carries a strip-shaped member or stayarm 7 which is provided with longitudinal slots 6, and a nonillustratedscrew, pin or the like extends through the slots 6 and into lateralportion of the frame of the panel 1 (which latter is also notillustrated in FIG. 6) so that, when the panel 1 is tilted from theposition of FIG. 1 to that of FIG. 2, the pin will slide in the slot 6and the member '7 can turn about its pivot connection with the glider 8.A locking member or detent means 24 of any suitable construction may beprovided for preventing undesired separation of the gliders 8 from theupper portion of the frame 4, that is from the portion carrying the rib3. It is secured to block 8 by a screw 25 or analogous means andreceived in the guide channel defined by the profiled rib 3.

My novel lifting means for the panel I is illustrated in FIGS. 7-10. Asshown there, it comprises two rods 9 which are mounted in the lowerportion 21 of the frame (see FIG. 8a) and which can be shifted in thedirection of the double-headed arrows seen in FIG. 7 by turning a crank10 (compare FIG. 8) which serves as the actuating means for the rods 9and which in known manner and via a known gear transmission effects thisshifting. The gear transmission itself is not shown in FIG. 8 because itis already well known in the art and forms no part of the novel liftingmeans. However, it will be appreciated that the rods 9 are to be eithersimultaneously drawn towards one another or to be simultaneously movedaway from one another, as indicated by the double-headed arrows in FIG.7.

Interposed between the bottom portion of the frame 4 and the bottomportion of the frame surrounding the panel 1 are two cages 13 which inthe illustrated embodiment have two oppositely and mutually inclined endfaces 12, (compare FIGS. 7 and I0) and of which the end faces 12 aredirected towards one another, the cages 13 being spaced longitudinallyso as to be located on opposite end portions of the panel 1. The bars 9are located in the space between the cages I3 and are provided withinclined surfaces 11 which will ride up on the respective end faces 12in the manner shown in FIG. 7 when the bars 9 are moved away from oneanother. In this manner the bars 9 lift up the panel I to the positionillustrated in FIG. 1. When the bars 9 are drawn towards one another, asshown in FIG. 9, the surfaces ll slide downwardly over the end faces 12and the bars 9 move downwardly with the underside of the panel 1,allowing the same to descend to the position of FIGS. 2, 3 and 5.

Located within each of the cages 13 are two roller bodies 14 providedwith axles or shafts 15 whose opposite end portions are each received inan elongated slot 16 provided in the opposite side walls I7 of therespective cage 13, the slots being located opposite one another andbeing inclined to the horizontal. This is clearly shown in FIG. 10. Eachof the roller bodies 14 is seated in an insert member 18 of trapezoidalshape and a wedge member 19 is located between the two insert members I8for motion-transmitting purposes.

The end faces 20 of the respective cages 13 abut against oppositelyupwardly inclined abutment surfaces 22 on end stops 26 which areprovided at the lower portion 21 of the frame bounding the panel 1.

It will be appreciated that when the rods 9 are moved away from oneanother as shown in FIGS. 7 and 8, the panel I is raised to itsuppermost position as shown in FIG. 4 in which the rib 3 of the frame 4is located within the confines of the channel 2 in sealing engagementwith the sealing means 5. In this position the panel 1 can be moved inthe direction of the arrow in FIGS. 1-3.

If it is desired to tilt the panel I to the position shown in FIG. 2,then the two rods 9 are moved towards one another as shown in FIG. 9, sothat the panel 1 moves to its lowermost position with the rib 3 beingwithdrawn from the channel 2, or rather the channel 2 being withdrawnfrom around the rib 3, as shown in FIG. 5. The weight of the panel isdistributed via the free ends 11 of the rods 9 and the abutment surfaces22 onto the cages 13. Now the panel can be tilted inwardly to theposition shown in FIG. 2 and is held against falling out of the openingof the frame 4 by the members 7.

From the position shown in FIG. 2, the panel 1 can now also be movedhorizontally, as illustrated in FIG. 3, and in this case the members 7with their associated glide members 8 move along with the panel 1. If itis desired to increase the stability of the arrangement, the two members7 which are located at opposite lateral sides of the panel I, could berigidly connected with one another. This is not shown, but how this canbe accomplished will be evident to those skilled in the art.

It will be appreciated that the arrangement shown in FIG. 10 guaranteesa constant and uniform loading of the individual roller bodies 14, andthat unevennesses in the lower portion 23 of the frame 4, on which theroller bodies 14 roll, are automatically compensated, with the provisionof the members 18 and 19 guaranteeing an almost absolutely constantposition of the panel 1 independently of any such unevennesses.

The opening obtained when the panel 1 is tilted to the position as shownin FIG. 2 can be almost freely selected, by the length of the slots 6provided in the member 7, and its maximum limit is determined only bythe extent to which it is practical to have the panel 1 make it projectinwardly into the room.

It will be appreciated that the construction disclosed herein is veryversatile, very simple, and very easy to operate. It will beadditionally appreciated that the location of the rib 3 within theconfines of the channel 2 when the panel is in the position shown inFIG. 4, guarantees that the window is tight and will remain tightregardless of whether ambient wind exerts pressure or section upon thepanel 1.

The cages 13 are loosely located in the recess portion 21 of the framesurrounding the panel I. This guarantees very simple maintenance andvery simple repair. The frame portion 2] may, if desired, have onlypoint contact with the cages 13 to prevent canting of the roller bodieswith respect to the frame portion 23 when the panel is tilted to theposition of FIGS. 2 and 3.

To provide increased protection against unauthorized opening of thepanel 1 from the outside, it may be advantageous if the construction issuch that the panel 1 can be shifted horizontally only when it is in astrictly vertical position. This can be done by providing arrestingmeans according to the concept such as illustrated in FIGS. 7 and 9wherein the frame portion 23 of the frame 4 is provided with a suitabledepression or recess 28 and wherein a prior analogous element 27 is fastwith the panel and enters into the recess 28 when the panel 1 isdisplaced vertically.

The glide members 8 may of course be made of various differentmaterials, as also the members 7. Metal, or particularly in the case ofthe glide members 8, synthetic plastic material are among those suitablefor this purpose. If it is not desired that the member 1 be horizontallyslidable when it is in tilted condition, that is in the manner shown inFIG. 3, then the construction illustrated may be modified so that thepanel 1 will be connected with the members 7 only when the panel 8 is inthe position illustrated in FIG. 1. Different ways will be evident tothose skilled in the art for accomplishing this, and by way of exampleit may be mentioned that there could be suitable coupling means providedon the members 7which would then be stationarily mounted on the frame4and on the panel 1, and which will engage when the panel 1 is movedhorizontally to its position illustrated in FIG. 1.

Finally, it should also be mentioned that the lifting means of FIGS.7-10 may be omitted, if desired, without omitting the sealing means ofFIG. 4. In this case it would then be necessary to make one of thelateral walls bounding the channel 2, or the rib 3, tiltable about anaxis extending in the direction of elongation of the opening of theframe 4, with biasing means being preferably provided to urge theparticular tiltably mounted member to its normal position correspondingto the position shown in FIG. 4. Of course, whichever one of theelements is mounted in this manner would have to be mounted for tiltingmovement about this axis to both sides of the same, and movement of thepanel 1 to the position shown in FIGS. 2 and 3 would then be effected bydrawing the panel 1 inwardly and at the same time deflecting thetiltably mounted component inwardly, whereas when the panel 1 is to bewithdrawn to its position shown in FIG. 1, it would be pressedoutwardly-as seen with respect to the interior of the room-with thetiltably or turnably mounted component yielding until the panel 1 is inits vertical position and being restored by its biasing means when theupper edge of the frame bounding the panel 1 has moved past it.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofconstructions differing from the types described above.

While the invention has been illustrated and described as embodied in awindow unit, it is not intended to be limited to the details shown,since various modifications and structural changes may be made withoutdeparting in any way from the spirit of the present invention.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims.

1. A window assembly comprising a frame surrounding a frame openingelongated in horizontal direction; a pair of window panels each having alower portion, said window panels being received within the confines ofsaid frame and together closing said opening; and means mounting atleast one of said window panels for horizontal sliding movement as aunit in the general plane of said opening as well as for tiltingmovement as a unit transversely to said general plane about a tiltingaxis extending in said lower portion of said one panel.

2. A window assembly as defined in claim 1, said frame having an upperframe portion bounding the upper edge of said opening and being providedwith a ridge element elongated in direction of sliding movement of saidone window panel; and said one window panel having an upper edgeprovided with an elongated upwardly open channel arranged to accommodatesaid ridge element in sealing relationship.

3. A window assembly as defined in claim 2, said means comprisingshifting means operative for shifting said one panel between an uppersliding position in which said ridge element is received in saidchannel, and a lower tilting position in which said channel isdownwardly spaced from said ridge element so that the latter cannotinterfere with tilting of said one panel.

4. A window assembly as defined in claim 3; further comprising arrestingmeans operative for preventing horizontal sliding of said one panel whenthe latter is in said lower position.

5. A window assembly, comprising a frame surrounding a frame openingelongated in horizontal direction, said frame having an upper frameportion bounding the upper edge of said opening and being provided witha ridge element elongated in said direction; a pair of window panelsreceived within the confines of said frame and together closing saidopening, at least one of said window panes having a lower edge portionand an upper edge provided with an elongated upwardly open channelarranged to accommodate said ridge element in sealing relationship; andmeans mounting said one window panel for horizontal sliding movement inthe general plane of said opening as well as for tilting movementtransversely to said general plane, said means comprising shifting meansincluding a pair of cages interposed between said frame and said loweredge in contact with the latter and spaced in direction of slidingmovement of said one window panel, said cages each having an upwardlyinclined surface facing the other cage, roller bodies in the respectivecages and rolling on said frame, and a pair of sliding bars receivedbetween said lower edge and said frame and each being slidable towardone of said inclined surfaces so as to ride up on the same and therebyshift said one window panel from a lower tilting position in which saidchannel is downwardly spaced from said ridge element, to an uppersliding position in which said ridge element is received in saidchannel.

6. A window assembly as defined in claim 5, said lower edge beingprovided with a downwardly open groove elongated in said direction, andsaid cages being loosely received in said groove.

7. A window assembly as defined in claim 6, said cages each having anadditional upwardly inclined surface facing away from and being upwardlyinclined in direction towards the respective first-mentioned surface,and said groove being pro vided with a pair of longitudinally spacedupwardly inclined surface portions against each of which one of saidadditional upwardly inclined surfaces abuts so that the respective cageis arrested.

8. A window assembly as defined in claim 5; further comprising aplurality of inserts in said cages and each engaging one of said rollerbodies, each of said roller bodies comprising a shaft about which itturns, and said cages having opposite side walls extending in saiddirection and being provided with a plurality of pairs of oppositeregistering slots inclined with respect to said direction, each slot ofeach pair receiving an end portion of one of said shafts.

9. A window assembly as defined in claim 8, said inserts being ofsubstantially trapezoidal outline; and further comprising wedge-shapedmotion-transmitting members received in said cages and interposedbetween successive ones of said inserts.

10. A window assembly, comprising a frame surrounding a frame openingelongated in horizontal direction; a pair of window panels receivedwithin the confines of said frame and together closing said opening; andmeans mounting at least one of said window panels for horizontal slidingmovement in the general plane of said opening as well as for tiltingmovement transversely to said general plane, said means comprisingelongated strip members each having a longitudinal slot and each havingan end portion connected to said frame at an upper frame portion thereoffor sliding movement in said direction and for turning movement about anaxis coincident with said direction, and connecting means extendingthrough the respective slots and connecting said strip members slidablyand turnably to an upper portion of said one window panel.

11. A window assembly as defined in claim 10; further comprising guidemembers mounted in said upper frame portion for sliding movement in saiddirection, said end portions of said strip members each being connectedto one of said guide members for turning movement about said axis.

12. A window assembly as defined in claim 11; further comprising detentmeans detaining said guide members against undesired separation fromsaid upper frame portion.

1. A window assembly comprising a frame surrounding a frame openingelongated in horizontal direction; a pair of window panels each having alower portion, said window panels being received within the confines ofsaid frame and together closing said opening; and means mounting atleast one of said window panels for horizontal sliding movement as aunit in the general plane of said opening as well as for tiltingmovement as a unit transversely to said general plane about a tiltingaxis extending in said lower portion of said one panel.
 2. A windowassembly as defined in claim 1, said frame having an upper frame portionbounding the upper edge of said opening and being provided with a ridgeelement elongated in direction of sliding movement of said one windowpanel; and said one window panel having an upper edge provided with anelongated upwardly open channel arranged to accommodate said ridgeelement in sealing relationship.
 3. A window assembly as defined inclaim 2, said means comprising shifting means operative for shiftingsaid one panel between an upper sliding position in which said ridgeelement is received in said channel, and a lower tilting position inwhich said channel is downwardly spaced from said ridge element so thatthe latter cannot interfere with tilting of said one panel.
 4. A windowassembly as defined in claim 3; further comprising arresting meansoperative for preventing horizontal sliding of said one panel when thelatter is in said lower position.
 5. A window assembly, comprising aframe surrounding a frame opening elongated in horizontal direction,said frame having an upper frame portion bounding the upper edge of saidopening and being provided with a ridge element elongated in saiddirection; a pair of window panels received within the confines of saidframe and together closing said opening, at least one of said windowpanes having a lower edge portion and an upper edge provided with anelongated upwardly open channel arranged to accommodate said ridgeelement in sealing relationship; and means mounting said one windowpanel for horizontal sliding movement in the general plane of saidopening as well as for tilting movement transversely to said generalplane, said means comprising shifting means including a pair of cagesinterposed between said frame and said lower edge in contact with thelatter and spaced in direction of sliding movement of said one windowpanel, said cages each having an upwardly inclined surface facing theother cage, roller bodies in the respective cages and rolling on saidframe, and a pair of sliding bars received between said lower edge andsaid frame and each being slidable toward one of said inclined surfacesso as to ride up on the same and thereby shift said one window panelfrom a lower tilting position in which said channel is downwardly spacedfrom said ridge element, to an upper sliding position in which saidridge element is received in said channel.
 6. A window assembly asdefined in claim 5, said lower edge being provided with a downwardlyopen groove elongated in said direction, and said cages being looselyreceived in said groove.
 7. A window assembly as defined in claim 6,said cages each having an additional upwardly inclined surface facingaway from and being upwardly inclined in direction towards therespective first-mentioned surface, and said groove being provided witha pair of longitudinally spaced upwardly inclined surface portionsagainst each of which one of said additional upwardly inclined surfacesabuts so that the respective cage is arrested.
 8. A wiNdow assembly asdefined in claim 5; further comprising a plurality of inserts in saidcages and each engaging one of said roller bodies, each of said rollerbodies comprising a shaft about which it turns, and said cages havingopposite side walls extending in said direction and being provided witha plurality of pairs of opposite registering slots inclined with respectto said direction, each slot of each pair receiving an end portion ofone of said shafts.
 9. A window assembly as defined in claim 8, saidinserts being of substantially trapezoidal outline; and furthercomprising wedge-shaped motion-transmitting members received in saidcages and interposed between successive ones of said inserts.
 10. Awindow assembly, comprising a frame surrounding a frame openingelongated in horizontal direction; a pair of window panels receivedwithin the confines of said frame and together closing said opening; andmeans mounting at least one of said window panels for horizontal slidingmovement in the general plane of said opening as well as for tiltingmovement transversely to said general plane, said means comprisingelongated strip members each having a longitudinal slot and each havingan end portion connected to said frame at an upper frame portion thereoffor sliding movement in said direction and for turning movement about anaxis coincident with said direction, and connecting means extendingthrough the respective slots and connecting said strip members slidablyand turnably to an upper portion of said one window panel.
 11. A windowassembly as defined in claim 10; further comprising guide membersmounted in said upper frame portion for sliding movement in saiddirection, said end portions of said strip members each being connectedto one of said guide members for turning movement about said axis.
 12. Awindow assembly as defined in claim 11; further comprising detent meansdetaining said guide members against undesired separation from saidupper frame portion.